supinfoClassEmails.js

// Go to http://www.campus-booster.net/Booster/students/classMembers.aspx
// Open your browser javascript console
// And execute this

var html = $('body').innerHTML
var regex = /http:\/\/www\.campus-booster\.net\/actorpictures\/([0-9]+)\.jpg/g
var ids = []

while (null != (match = regex.exec(html))) {
    ids.push(match[1])
}
var emails = ids.map(function (id) {
    return id+'@supinfo.com'
})

var emailsList = emails.join(', ')

console.log(emailsList)